Varnish

Varnish Cache is a web accelerator also known as an HTTP accelerator. You can install it in front of any server that speaks HTTP and configure it to cache the contents. Varnish Cache is very, very fast and will improve the loading speed of your website. One of the main virtues of Varnish Cache is the flexibility of its principal configuration mechanism, VCL, which enables you to specify how incoming requests should be tackled.

Memcached

Memcached is a generic memory caching system for increasing the loading speed of dynamic database-powered websites. It is used to decrease the number of times an external data source (such as a database or API) is read by caching data and objects in RAM. The Memcached system uses a client/server architecture. The Memcached system is used by some of the most traffic-intensive websites on the World Wide Web and is supported by popular web applications like Joomla and WordPress.

Node.js

Node.js is a software platform for writing scalable Internet apps. Built on Chrome's JavaScript runtime, Node.js uses an event-driven, asynchronous I/O model that makes it lightweight and efficient, excellent for high-performance content-rich network apps. Node.js uses Google's V8 JavaScript engine, libUV, and a number of built-in libraries.

InnoDB

InnoDB is the default database engine for the MySQL open-source relational database management system. A database engine is the underlying software component that a database management system uses to create, read, update and delete data from a database. Its latest release offers serious improvements in performance, security and usability. InnoDB offers the standard ACID transaction properties, as well as foreign key support. It is included by default in most binary distributions from MySQL AB.